Carbureter.



A. A. FREVERT.

CARBURETER.

APPLICATION FILED APR. 14.1915.

Patented 00m. 9,1917.

3 SHEETS-SHEET LQQLLQJAEQO A. A.YFREVERT.

CARBURETER.

APPLICATION FILED APR. 14.1915.

' Patented Oct. 9,191?

3 SHEETS-SHEET 2- A. A. FREVERT.

GARBURETER.

APPLICATION FILED APR. 14. I915.

Patented Oct. 9, 1917.

3 SHEETS-SHEET 3.

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Application filed April 14, 1915. Serial No. 21,469.

To all whom it may concern Be it known that I, ALBERT A. FREVER'I', a citizen of the United States, and resident of Charles City, in the county of Floyd and State of Iowa, have invented a certain new and useful Carbureter, of which the following is a specification. p

The object of my invention is to provide a carbureter of simple, durable and inexpensive construction.

A further object is to provide a carbureter which is adapted to be used with two types of fuel, for instance kerosene and gasole'ne.

Still a further object is to provide such a carbureter adapted to be connected with two sources of fuel supply, and by means of a slight adjustment to be used with either of two fuels.

Still a further object is to provide such a carbureter having priming means adapted to be used with either of the fuels which may be employed in the carburetor.

Still a further object is to provide such a carbureter adapted to be connected with two sources of fuel supply, and having parts capable of being adjusted for properly mixing with air and vaporizing either of the fuels.

My invention consists in the construction, arrangement and combination of the various partsof the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, ..nd illustrated in the accompanying drawings, in which:

' Figure 1 shows a front-elevation of a carbureter embodying my invention, showing the manner in which the carburetor is connected with the intake manifold and with of the carbureter, taken on the line 4-4 of Fig. 9, the primer being shown in section taken on the line 4e-4 of Fig. 2.

Fig. 5 shows a detail, sectional view. taken on the line 55 of Fig. 4, and also on the line 55 of Fig. 8.

Specification of Letters Patent.

Patented Oct. 9, i917.

' Fig. 6 shows a detail, sectional view, aken on the line 6-6 of Fig. 8.

r Fig. 7 shows a detail, sectional view, takenon the line 77 of Fig. 9.

Fig. 8 shows a detail, sectional view, taken on the line 88 of Fig. 9 and Fig. 9 shows a detail, central, vertical, sectional view of the carbureter, taken on the line 9- 9 of Fig. 3,-one of the float chambers being shown partially in front elevation.

In the exemplification of my invention illustrated in the accompanying drawings, I- have shown the central, hollow carburetor body indicated by the reference character 10, and having the laterally extending portion 11, having the cylindrical extension 12 open at its outer end. Suitably mounted in the extension 12 is a damper valve 13, having a stem-14L on which is a lever 15. The main air supply to the carbureter may be controlled by the valve 13. The extension 12 is on what I shall call, for convenience,

the front side of the carbureter.

On opposite sides of the carbureter are two float chambers 16 and 17, having the removable top or cover members 18 and the downward extensions19. Mounted in each downward extension 19 is a collar or fitting 20 having a central, vertical opening 21, the upper portion of which forms a valve seat 22. Seated on the seat 22 is a valve 23, having a stem 24. slidably mounted in a suitable'bearing 25 in the top or cover member 18. Fixed on the upper portion of the stem 24 is a collar 26, having spaced annular flanges 27.

Extending downwardly from the top member 18 on opposite sides of the stem 24., are brackets 28. Pivoted to the lower end of the brackets 28 at points between their ends, are arms 29. One end of each arm 29 stands. adjacent to the collar 26 between the .reaches a certain height to engage the weights 30, thereby raising them and forcing the valve 23 to its seated position.

Screwed into the extension 19 below the fixture 20, is a fixture 32 having a central opening into which is screwed the end of a tube 33, Whichis adapted to furnish the fuel to the float chamber. The float chambers are of substantially the same construction.

On the lower part of-the chamber is a downward extension 34, shown in Figs. 4 and 9. Formed on the extension 34 is a lateral extension 35. An opening 36 extends downwardly from the bottom of the chamber 10 into the extension 34. Rotatalily mounted in the extension 35 is a valve 37, havinga stem 38 extending outwardly from the extension 35. On the outer endof the stem 38 is a controlling lever 39.

In the bottom of each float chamber 16 and 17 is a downwardly extending opening or passage 40. A horizontal passage 41 communicates with the lower end of each opening 40, and extends to the opening in the extension 35, in which is mounted the valve 37. The valve 37 is substantially the shape of a truncated cone, as illustrated. in Fig. 4. In the surface of the valve 37 are spaced longitudinally arranged grooves 42 and 43. The grooves 42 and 43 are so arranged with relation to the inner ends of the passages 41 that in one position of the valve 37 the groove 42 registers with the inner end of the passage 41, as illustrated in Fig. 8, whereby fuel may flow from the chamber 16 through the passages 40 and 41 and the groove 42 to the opening in the extension 34, while in another position of the valve 37 the groove 43 registers with the inner end of the opposite passage 41, whereby fuel may flow from the float chamber 17 to the opening in the extension 34. The lower end of a fuel nozzle 44 is screwed into the opening in the bottom of the chamber 10, as illustrated in Figs. 4 and 9. The lower part of the fuel nozzle 44 communicates with the opening in the extension 34 and the upper part forms a discharge nozzle 44 Suitably mounted within the chamber 10 is a Venturi tube 45, so arranged that the narrowest part of the passage therethrough is just below the level of the point of discharge from the discharge nozzle 44 IVithin the chamber 10 above the Venturi tube 45, is mounted a second Venturi tube 46, the end of which receives the upper end of the Venturi tube 45. The Venturi tube 46 is arranged for vertical reciprocation. It is PIOXldQd on one side with a rack bar 47 adapted to coact with the pinion 48. The pinion 48 is mounted on a short shaft 49, on the outer end of which is the-lever 501 The purpose and operation of the Venturi tubes will be hereinafter more particularly referred to, and is substantially the same as described in the application of Harold E. McCray, Serial Number 817,716, filed February 9, 1914, issued September 14, 1915, Number 1,153,436.

aaeaese There is provided a priming system as a part of my improved carbureter, for each of the float chambers, and therefore for each kind of fuel which may beemployed. The construction of the mechanism of each priming system is the same.

Formed on the rear part of the chamber 10 is an extension 51 of sufficient size to contain the passages hereinafter described. The priming system connected with the float chamber 16 comprises a vertical receptacle or passage 52 in the extension 51, communieating at its lower end with a laterally extending passage 53. The passage 53leads to the passage in which the valve 37 is mounted. It might be mentioned in this connection that the priming system for the float chamber 17 includes a passage 52 similar to the passage 52, communicating at its lower end with the laterally extending passage 53 similar to the passage 53.

grooves register with the inner ends of the passages 53.- and 53. Spaced from the pas- I sages 52 and 52 on the side away from the chamber 10, there are formed in the extension ,51 vertical air passages 54 and 54 At the lower ends of the passages 54 and 54 are laterally extending passages 55 and 55*, which lead to the passage in which the valve 37 is mounted. Screwed into the top of the extension 51 above each passage 52 and 52, is a hollow plug or fitting 56.

In the upper part of the extension 51 are passages 57 leading respectively from the upper part of the passage 54 to the upper part of the passage 52, and from the upper part of the passage 54 to the upper part of the passage 52 The screw threaded plug 56 is so arranged that by screwing it up and down the size of the passage 57 may be varied, as illustrated in Fig. 4.

At the upper end of the chamber 10 is mounted a throttle valve 58 on a stem 59, extending outwardly through the wall of the carbureter shell, and having on its outer end a lever 60. In the outer part of the wall of the shell or chamber 10 is apassage6l communicating with the discharge end of the passage from the chamber 10 at such a point that when the throttle valve 58 is in level horizontal position, at least part of the open inner end of the passage 61 is above the throttle valve so that suction may be established from the priming well to the engine while practically no suction occurs through the carbureter. At the outer end of the passage 61 is a passage 62 extending laterally from the passage 61 in both directions.

Tubes 63 and 63 communicate with the plugs 56 and with the opposite ends of the passage 62, as illustrated in Figs. 2 and 4.

The passages 52 and 52 are priming receptacles for fuel, and the passages 54 and 54 are air intake passages. The admission of air to the passages 54 and 54 is controlled in the following manner.

' The valve 37 is provided with a flat surface 64, and above the flat surface 64 is an upwardly opening passage throughthe upper wall of the extension 35. The flat portion 64 is so arranged that by turning the valve to one position the passage 65 may be placed in communication with the assage 55, while by turning the valve 3 to another position the passage 65 may be 62 and the passage 63 will draw air from the passage 54 and fuel vapor from the priming well 52, for supplying an excep tionally rich mixture for starting the enine. a It will be understood that the operation and construction of the other priming device is the same as that just described.

Before proceeding with the description of the construction of the other parts of my improved carbureter, I will explain the prac tical operation of the parts already described. 4

It will be seen that the two float chambers are placed adjacent to the shell which forms the mixing chamber and receives the discharge nozzle 44, and said float chambers may be made integral with the carbureter shell if desired. Assuming that each float chamber is connected with a suitable source of fuel supply, and that two fuels are being used, when it is desired to start the car with gasolene the valve 38 is properly operated to connect the float chamber containing gasolene with the proper priming well. At

the same time air is admitted over the top of the proper priming well. WVhen the engine is turned over the rich mixture will be drawn past the throttle in the manner already described, and into the intake manifold and from there through the cylinders. When the engine has been started the throttle is opened, whereupon the suction through the priming well will be reduced to the point where it is almost immaterial,

and the fuel will be drawn from the nozzle 44 in the ordinary way.

Assuming that after the engine has been run for a short time on gasolene, it is (16.-

lene.

sired to change the fuel, then the lever 39 is operated to change the position of the valve 37 for connecting the tube 44 with the A float chamber containing the other fuel. At the same time the venturi tube 46 is operated to change the opening around the upper end of the tube 45 for providing proper air supply for the new fuel. The advantages of using the Venturi tube are shown in the, application of Harold E. McCray, Serial Number 805,456, filed December 8, 1913, and a further description of the operation of the Venturi tube will not be herein made, except to state that by the use of the adjustable Venturi tube the carbureter may be readily adapted for use with either of two fuels and to furnish a proper mixture of air with either of the fuels.

I will now describe an additional feature whereby my carbureter is adapted for use with two fuels such as kerosene and gaso- I have found by experiments that gasolene when exploded in the cylinder burns more slowly than kerosene, andthat when an engine has been adjusted and timed for use with gasolene that the use of the kerosene tends to cause a knock. To elimi-- nate this knock I have made a provision for slowing down the burning of the kerosene so that it will burn, when ignited, at more nearly the same rate as gasolene. For accomplishing this purpose I have provided at one side of the upper end of the shell 10 an extension 66 opposite the throttle valve 58. On one end of the stem 59.0f the throttle valve- 58 is a substantially cylindrically shaped valve 67, having one side cut awayat 68, and having at its outer end a cut-away portion .69. Screwed into the extension 66 is a hollow cylindrical plug 70, which surrounds the valve 67 and is provided with a plurality of openings 71 in its outer wall.

The extension 66 is provided with a passage 72, so arranged as to register with the different openings 71 in various positions of the cylinder 70. The openings 71 are of a variety of sizes for regulating the flow of fluid from the passage 72. It will be understood that when the throttle is open the ortions 68 and 69 are so arranged that uid may pass through the passage 72 and through the valve 67 to mingle with the fuel mixturewhich passes the carburetor on the way to the intake manifold 73.

The passage 72 is adapted to be connected with the exhaust of the engine in the manner hereinafter described, for the purpose of supplying a certain amount of exhaust gases to the incoming mixture. In endeavoring to furnish a proper mixture of kerosene to run an engine which has been regulated and timed for gasolene, I have found that varying the amount of ordinary air will not accomplish the purpose, but by mixing with the incoming kerosene fuel a certain amount of the dead exhaust gases, the explosion of the kerosene will be somewhat retarded so that the kerosene and the gasolene will burn about the same.

At the upper end of the shell 10 is a circumferential, annular flange 74. Above the flange 74 is a heater substantially like that described in the application of Harold E. McCray, Serial Number 805,456, filed December 8, 1913, comprising a cylinder 75 having upper and lower ends 76 and 77. On the upper and lower ends are annular flanges 78, one of which is bolted to the flange 7 4. Extending longitudinally through thecylinder 75 and through the top and bottom 76 and 77, are heater tubes 79, the lower ends of which communicate with the discharge end of the chamber 10 above the throttle 58. The upper end of the heater is designed to be connected with the intake manifold 73. I

The exhaust pipe 80 of the engine is arranged to discharge into the upper portion of the cylinder 75, and said cylinder is arranged to discharge the exhaust gases through a pipe 81.

A port 82 communicates with the interior of the cylinder 75 and with the passage72 for supplying a limited amount of exhaust gases to the fuel passing to the intake manifold.

In the practical operation of my' improved carbureter, it will be seen that the fuel supply to the engine'is heated -in the tubes 79. When desired the plugs 7 0 can be rotated for permitting a certain amountof exhaust gases to be supplied to the fuel. By rotating the plug 70 to different positions the amount of exhaust gases thus furnished may be regulated. The supply of exhaust gases may be entirely shut of if it is desired to run on gasolene without'using any of the exhaust gases. In further explanation .of my improved carbureter, it may be said that the carbureter may be connected with two sources of in the float chambers.

fuel supply, and the flow of fuel from the two sources will be regulated by the floats The nozzle 44' may be readily and easily connected with either source of fuel supply. The air valve 13, of course, may be regulated'at any time to suit the needs 'of the engine, but is mainly used to reduce the supply of cold air when starting the engine in cold weather. I

In connection with the two sources of fuel supply, the carbureter may be regulated by varying the position of the upper Venturi tube 46 for securing the proper mixture of air and properly regulating the speed of the passage of the air and fuel for the different fuels, depending, of course, also upon the suction from the engine. In connection with the control secured by the Venturi tube, I have also provided means for furi,a sense well above the discharge nozzle, so that,

there is no danger of suction from the priming wells when the throttle is open.

It should also be noted that the floats in the respective float chambers are so arranged that the fuel will stand in diflerent heights in the' nozzle when the different chambers are placed in communication with the nozzle. This is necessary on account of the difl'erences in specific gravity between kerosene and gasolene, for instance, on account of Which it is desirable to have the fuel stand in the nozzle at different heights when the diflerent fuels are being used.

It will also be noted that the member 56 is vertically adjustable with relation to the portion 57, whereby the passage from the air passages 54 and 54 to the priming wells 52 and 52" may be varied for regulating the mixture drawn from the priming wells.

It will be understood that changes may be nilade in the arrangement and construction of t e out eparting from itsessential features and claims. I I claim as my invention: 1. Tn a carbureter, the comblnation of a shell forming a mixing chamber, a dis- (parts of my lmproved carburetor withnishing the exhaust gases to the fuel for recharge nozzle therein, float chambers adjacent to said shell, means whereby either float chamber may be placed incommuni-' cation with said nozzle, a throttle valve for controlling the discharge from the mixing chamber, priming wells adapted to communicate with the respective float chainbers, air passages communicating with the upper ends of the respective priming wells, passages leading from the priming wells to the mixing chamber above the throttle valve, and means for simultaneously 'c0n-- trolling the flow of fueland air to the respective priming wells and air passages adjacent thereto, and for placing the respective float chambers in communication with said nozzle. 4

2. In a carb'ureter, the combination of a shell forming a mixing chamber, a discharge nozzle therein, float chambers adjacent to said shell, means whereby either float chamber may be placed in communication with said nozzle, a throttle valve for controlling the discharge from the mixing chamber, priming wells adapted .to communicate with the respective float chambers, air passages communicating with the upper ends of therespective priming wells, and passages leading from the priming wells to the mixing chamber above the throttle valve, and a single valve capable in one position of admitting fuel from one float chamber to the nozzle and to one priming Welland of admitting air to the air passage adjacent to the last named priming Well, and in another position of admitting fuel from the other float chamber to the nozzle and to the other priming well and air to the air passage adjacent to the other priming Well.

8. In a carbnreter, the combination of a shell forming a mixing chamber, a discharge nozzle therein, float chambers adjacent to said shell, means whereby either float chamber may be placed in communication with said nozzle, a throttle valve for controlling the discharge from the mixing.

chamber, priming wells adapted to communicate with the respective float chambers, air passages communicating with the upper ends of the respective priming Wells,

passages leading from the priming wells to the mixing chamber above the throttle valve, and means for regulating the amount of air passing from said air passages to said priming wells.

Des Moines, Iowa, March 16, 1915.

ALBERT A. FREVERT.

Witnesses:

HARLEY lVILLIAMs, ERVIN E. DE LIENNE. 

